Let's talk IR Illuminators!

Discussion in 'General Electronics Chat' started by Mike33, Sep 11, 2014.

  1. Mike33

    Thread Starter AAC Fanatic!

    Feb 4, 2005
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    Hi,

    Here's an interesting request for information!

    My buddy is....ok, don't laugh....a ghost hunter. Yup, for real! He has a lot of fun with it with friends, and they do catch some interesting "data" at times.

    He's asking me to come up with a better IR illuminator for use with his digital NV cam. He has seen a cheap one with a few bulbs on it....he'd like me to figure out how to make two of these with 12 bulbs instead of the 8. We can't lay hands on the thing (he just has a pic...yeah, I know....).

    I've used IR LEDs in the past but never bulbs....we'd like to power this off 1 or 2 9V batteries per unit. Does anyone have ANY info on where I can find individual bulbs that would be appropriate for this use? The bulbs are about the size of old=fashioned christmas tree lights, not big heat lamps or anything.

    Guy's talking about throwing light out 100' with a DIY thing...I've tried to tell him about inverse squares and the like, but he's pretty adamant, LOL....thanks for any suggestions!
     
  2. doller

    New Member

    Sep 28, 2012
    14
    3
    Gotta love infrared. Go for LEDs, bulbs are an overkill for hunting imo.

    I sometimes leave a camera in the basement. There is... stuff happening. But not always. Next will be a wireless cam in certain buildings with certain history. The nice thing is nobody can see and snatch your camera and illuminators.

    Best to use the 940 nm wavelength variety, they will never visibly glow.

    There are already some cheap hardcore infrared high power leds for the same price as normal ones. Best thing is, since they are far red, the Uf is very low, as low as 1.2V. Several AA rechargeables in parallel will feed a 5W star for a whole night.


    [​IMG]
     
  3. Mike33

    Thread Starter AAC Fanatic!

    Feb 4, 2005
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    Nice, thanks! Yeah, I priced them on Ebay, and you can get a 20 pack for about $3! So there we go. I'll make him 2 boxes with 20 in each, so he can put them on a "T" and spread the 'beams' for a wider angle. Things are easier when you can source the parts...he didn't 'get' that. The bulbs are way too cumbersome to use and hard to find!
     
  4. doller

    New Member

    Sep 28, 2012
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    Make sure you get a decent power units, 20 mA is not going to work very well. The photos above show a bunch of 50 mA conventional leds in action.

    Also what I meant to say is that today you can already buy a high power bead LED for maybe $10 a piece, i.e. 1400mA. Makes it easier to mount in a torch for example.

    [​IMG]
     
    shyckh likes this.
  5. Mike33

    Thread Starter AAC Fanatic!

    Feb 4, 2005
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    Looks like this one might be our guy, eh? http://www.ebay.com/itm/1pc-5W-Infr...143?pt=LH_DefaultDomain_0&hash=item5669a19b1f

    As with any LED, I can adjust the current as appropriate, right? I.E., the 1400mA is the MAX rating, you set what you like with a dropping resistor....I have to decide on what to use to power these with, and come up with a reasonable life expectancy. I like the idea of using one unit like this, tho, rather than having to make a box with 20 indiv. LEDs that have no reflector!
     
  6. doller

    New Member

    Sep 28, 2012
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    Yes, the same principles apply.
     
  7. RichardO

    Well-Known Member

    May 4, 2013
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  8. Mike33

    Thread Starter AAC Fanatic!

    Feb 4, 2005
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    Thanks for the idea, Richard, but I think power could be a constraint with those. He just wants me to make something "ghetto" for him, rough & dirty. The 5W units are about $6 on Ebay, so we'll try them, but if they aren't good enough he's going to have to fork over the dough for something nice like one of those! ;)
     
  9. ronv

    AAC Fanatic!

    Nov 12, 2008
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    Don't give up on the smaller (say 100 ma) ones. If you use a 5 watt one the current will lead you away from a resistor and into a current source. It will also need a heat sink.
     
  10. Mike33

    Thread Starter AAC Fanatic!

    Feb 4, 2005
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    Honestly, I'll probably try both! If he wants to purchase the 5W, ok. But i'll be grabbing a bunch of the 'normal' IR LEDs as shown above, just to satisfy my own curiosity! ;) I like the control you have when you can set up parallel strings, so that you can run a bunch of LEDs but manage the power dissipation...good call on your part re. that issue, Ron....
     
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